NAPLES - Massimiliano Allegri has the central defender he's been waiting for. Napoli has finalized the signing of Benoît Badiashile, born in 2001, from Chelsea. The move will strengthen a defense currently hampered by injuries to Alessandro Buongiorno, Luca Marianucci, and Sam Beukema. The deal was concluded on a €3 million loan, plus €1 million in bonuses, with a €27 million purchase option. The total value of the deal could therefore reach €31 million. Badiashile expected for medicals at Villa Stuart. The French defender is expected in Italy today, while on Wednesday…